When a building is equipped with a properly designed, installed, and maintained sprinkler system, an offensive fire attack takes on an entirely different character. Fire department operations are much easier, and the risk to firefighters is significantly reduced. The primary tactic in a sprinkler-protected building is to let the system do its job while supporting the system. Efforts should be directed toward maintaining the system in a fully operational status, while laying backup lines for final extinguishment.

Commercial-type automatic sprinkler systems that meet the requirements of NFPA 13, Installation of Sprinkler Systems, have an exceptional record of controlling fires. Large losses of life and property are practically nonexistent in buildings equipped with a properly operating sprinkler system. When large-loss fires do occur in these properties, some degree of human error is generally involved.

A common operational error at properties protected by automatic sprinkler systems is shutting down the system prematurely. Firefighters working at the scene must be sure the fire is totally under control before they shut down the system. When the system is shut down, a firefighter should be assigned to stand by the main control valve in case it becomes necessary to reopen the valve quickly. This firefighter should be equipped with a radio or some other means of communication.

Another common operational error is inadvertently “stealing” water from an automatic sprinkler system by operating fire department pumpers from the same water supply. A properly designed sprinkler system should have a calculated water supply requirement that includes enough water to support hose streams. However, the incident commander must be extremely careful to avoid depleting the sprinkler system of the water pressure and volume necessary to support operating sprinklers properly. The best practice is to connect attack lines to a water supply that is separate from the one supplying the sprinkler system. If a decision must be made between using hose lines and properly supplying the sprinkler system, it is usually best to supply the sprinkler system using the fire department connection.

In many cases, the sprinkler system will control the fire, but it may not completely extinguish a fire that is shielded from direct water contact. In a warehouse, for example, commodities may be stored on shelves that do not allow the sprinkler system to apply water directly on the burning stock. Hand lines must be in place, ready to extinguish any remaining fires. In rare cases, usually where sprinkler piping is damaged, it may be necessary to shut the system down so that enough water is available for manual suppression. If a sprinkler system is having difficulty controlling the fire, it is more desirable to have hose lines at strategic locations and secure additional off-site water supplies than to shut down the system if the sprinkler piping is still in place.

These are just some of the issues that fire department procedures should address when firefighters are working in structures protected by fire protection systems. Pre-incident planning is essential for any building protected by an automatic fire suppression system.

During pre-incident planning, firefighters should familiarize them-selves with the general layout of the building and know the location and operation of control valves, fire pumps, and fire department connections in advance. System limitations and peculiarities should also be addressed during pre-incident planning.

For more on the Multiphase Study on Firefighter Safety and Deployment of Resources, visit firereporting.org.